Dubin-Johnson syndrome

Pronunciation: dū′bin jon′sŏn

Definition: an inherited defect in hepatic excretory function characterized by jaundice with levels of serum bilirubin up to about 6 mg/dL, over half of which is conjugated, and excretion of abnormal proportions of coproporphyrin I in urine. There is also retention of a dark pigment in the hepatocytes that is derived either from melanin or catecholamines, but otherwise liver histology examination provides normal results. Oral cholecystogram fails to visualize the gallbladder; excretion of test substances (bromosulfothalein) by the liver is abnormal. The basic defect is apparently in canalicular transport. No therapy is necessary; autosomal recessive inheritance caused by mutation in the canalicular multispecific organic anion transporter gene (CMOAT) on 10q.

Synonym(s): chronic idiopathic jaundice

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